Paliperidone extended-release tablets in schizophrenia patients previously treated with risperidone

To assess the effect of paliperidone extended-release (ER) tablets in patients with acute symptoms who had previously received risperidone. Data for this post-hoc analysis were pooled from three 6-week, double-blind, placebo-controlled trials in patients treated with paliperidone ER 3-12 mg/day or placebo. Patients had to have received risperidone for >= 4 weeks within 2 weeks of study entry. Assessments were done using the Positive and Negative Syndrome Scale, Clinical Global Impressions-Severity scale, Personal and Social Performance scale, the Simpson-Angus Scale, and adverse event (AE) reports. Altogether, 198 patients (paliperidone ER, n = 142; placebo, n=56) met the established criteria. Mean (SD) duration of prior risperidone treatment and dose were 418.8 (572.8) days and 4.4 (2.5) mg/day for paliperidone ER and 527.0 (805.3) days and 4.1 (2.5) mg/day for placebo. Study completion rates were 61.3% for paliperidone ER versus 42.9% for placebo. At endpoint, paliperidone ER showed significant improvement versus placebo (P<0.05) in Positive and Negative Syndrome Scale, Clinical Global Impressions-Severity, and Personal and Social Performance scores. Mean baseline Simpson-Angus Scale scores were low, with no significant changes at endpoint in either group. AEs >= 10% with paliperidone ER versus placebo were headache (16.2 vs. 16.1%), insomnia (14.1 vs. 16.1%), and agitation (8.5 vs. 10.7%). AE-related discontinuations were 2.1% with paliperidone ER and 5.4% with placebo. In patients who had received risperidone previously but remained sufficiently symptomatic for enrollment, paliperidone ER was significantly more effective than placebo in reducing symptoms and producing functional gains.